Cleansing and polishing agent



,UNITED STATES PATENT OFFICE.

RUDOLPH A. KUEVER'OF IOWA CITY,

CHICAGO, ILLINOIS,

IOWA, ASSIGNOR '10 PEPSOIOEN'I COMPANY, OF A CORZPORA'IION OF ILLINOIS.I

cnnn'nsme AND romsnme AGENT.

No Drawing.

My invention relates more particularly to an improved dentifrice to becompounded in the form of either a paste or a dry owder,

but its utility is not restricted to sue use as the substances describedand claimed possess advantages for other uses polishing agents. mustpossess certain as cleansing and A dentifrice, however, propertles whichare not necessary in polishing and cleansing agents for other uses.

It has been discovered having an that dentifrices g acid reactionpossess advantages over substances or mixtures of substances having aneutral or alkaline reaction, the

, generally accepted explanation of this fact being that stimulates thealso increases In addition to having anthe acidity ofsuch a-dentifriceflowbf the saliva and that it the alkalinity of the saliva.

acid reaction it p is also' essential that a dentifrice consist of orcont in a substance which in the powdered form will have the necessarymechan ical action when rubbed or brushed upon the teeth to eifectthecleansing and polishing of the tooth surfaces, used for this purposehardness as to perform and the substance should be of such "thecleansingand polishing functions without injurious or, if

possible, without any, substance, and it should be of solubility afterthe cleansin and polishing is but will enter intmolution in thethereafter.

the mouth shortly abrasion of the tooth of such a degree that it willresist solution until efiected uids of The necessity for the degree ofsolubility above described resides in of the principal sources 0 thefact'that one f trouble arising from the use of dentifrices consists inthe lodgment under the gum margins of part1- cles of the polishing mentof the polishing agent. agent under the gum This lodgmargins gives riseto irritation and inflammation and eventually exposes the gums toinfection. This disadvantage may be eliminated by employing a polishingand cleansing agent that is sufficiently soluble to enter .into solutionin the mouth fluids within a comparatively Agents possessing describedquickly 7 under the gum margins w short timev after the cleansing beeneffected;

hereby the cause hardness and solubility.

. Application filed December 12, 1924. Serial No. 755,369.

of irritation is eliminated before any harm ful effect is produced. v

I have found that the degree of solubility of an efiicient polishing andcleansing agent for the purpose of a dentifrice is less than 1 in 200,and that satisfactory results in respect to solubility are attained bythe use of an agent having a solubility in the neighborhood of. 1 in1200. This degree of solubility insures that the polishing andcleansoperation but will lodgment under effect has cleansing andpolishin enter into solution a er the gums before any injurious beenproduced. a

The degree of hardness of a cleansing and polishing agent used upon theteeth should be such as to avoid any abrasion whatsoever of the toothsubstance, but should at the same time be of such hardness as to effectthe necessary cleansing and polishing.

In compounding a dentifrice there is no difiiculty in imparting to itthe necessary acid reaction by the use of suitable fruit acids or otheracid substances provided the polishing and cleansing agent and otheringredients, if any, do not by their alkalinity neutralize the acid oracid substance.

I have discovered that certain salts consisting of inorganic basescombined with bydroxy organic acids possess the requisite combination ofproperties, being neutral in reaction and possessing the proper degreeof Calcium carbonate in the form of ordinary chalk has heretofore beenused to some extent as a dentifrice but neither in hardness nor insolubility does it conform to the requirements above described. I havefound, however, that the substitution for carbonic acid of certain ofthe hydroxy organic acids produces with calcium a neutral salt havingthe degrees of hardness and solubility above described, and thatsubstantially similar compounds are formed by the combination of thesehydroxy organic acids with other elements of the alkaline earth group.Among the salts which I have found especially adapted for use as adentifrice is calcium citrate. This substance is neutral in reaction, isof the requisite solubility and has a hardness of about 1 upon thestandard scale of hardness. For

agent will resist solution during the efficient cleansing and polishingthe degree of hardness should not be materially less than 1 and shouldbe less than 3.5, the hardness of the tooth structure ranging ordinarilyfrom 3.5 to 7 p For use as a dentifrice it is of course necessary thatthe polishing and cleansing agent be innocuous in addition to possessingthe other properties above described. I have found that these propertiesare fulfilled by calcium citrate and also by calcium tartrate andstrontium tartrate, and that certain other alkaline earth salts ofhydroxy organic acids, such as barium citrate, possess the requisiteproperties for polishing and cleansing but are unavailable for use indentifrices by reason of other properties.

The freedom from abrasive effect upon the tooth substance of the saltsreferred to above of hydroxy organic acids appears to be related notonly to their degree of hardness but also to some other property, as Ihave found that calcium citrate produces no abrasive action upon theteeth while other compounds composed entirely of inorganic substancesand of substantially the same degree of hardness do abrade, the toothstructure. I have subjected gold crowns and tooth structure to theprolonged polishing action of calcium citrate without producing anyabrasion whatsoever and resulting onl in the production of a high polishwhile similar use of polishingagents of substantially equal hardness andcomposed entirely of inorganic substances has resulted in destructiveabrasion. This indicates that the salts which I employ possessproperties not found in purely inorganic substances or insalts of thecharacter of calcium carbonate, and that these properties are especiallyadvantageous in a dentifrice and also useful for other purposes.

Following is an illustrative formula of a dentifrice embodying myinvention:

i Parts.

The above formula is for the preparation of a dentifrice paste. Asabovestated, calcium citrate is neutral in reaction. The free citric acidimparts the necessary acidity. Other fruit acids or suitable substanceshaving an acid reaction may be used in place of citric acid. The gumsare used as a binder and serve to preserve the homogeneousconsistency ofthe paste.

While in the following claims I refer to my invention as a dentifrice Icontemplate its use for other purposes as coming within the scope of theinvention.

I claim as my invention:

1. A dentifrice comprising a cleansing and polishing agent consisting ofcalcium citrate.

2. A dentifrice comprising calcium citrate and a substance having anacid reaction.

3; A dentifrice comprlsing calcium citrate and a binder mixed to form apaste.

4. A dentifrice comprising calcium citrate and glycerine. 4

5. A dentifrice comprising calcium citrate, a binder and glycerine mixeto form a paste.

Signed at Iowa City, Iowa, this 9th day of Dec., 1924.

RUDOLPH A. KUEVER.

